1. Field of the Invention
The present invention generally relates to computer keyboards and, more particularly, to a split keyboard that is composed of two sets of keys and uses wrist position to multiply the interpretations of the two sets of keys.
2. Background Description
There are many drawbacks associated with the existing keyboard designs and methods for capturing keystrokes.
First, existing keyboard designs require unnatural, fixed hand positions leading to discomfort, muscle fatigue, and repetitive stress injuries (RSI). Specifically, traditional, flat keyboards require the user to rotate their wrist inwardly and to hover their hands above the keys. Furthermore, the hands must be brought from the user""s sides to the center of their body and kept there. Making matters worse, there is little need to move the hands from these positions. These positions require constant muscle pressure without movement, which leads to muscle fatigue, discomfort and pain. The continuous finger movements with the hands in these stressed positions lead to repetitive stress syndrome problems.
Second, the hands must move relative to the keys, making touch typing difficult. Touch typing requires the use of memorized, easily repeatable, high precision gestures to indicate the desired character. Fine motor movements, such as finger gestures, are ideal for this purpose. Gross motor movements, such as arm movements, are very poor for this purpose. Traditional keyboards make the most commonly accessed characters reachable via fine motor movements. The less often used keys, such as numbers, punctuation marks, function keys, the xe2x80x9cTxe2x80x9d and xe2x80x9cYxe2x80x9d, the xe2x80x9cEnterxe2x80x9d, xe2x80x9cShiftxe2x80x9d, and xe2x80x9cBackspacexe2x80x9d keys, require a combination of fine and gross motor movements. Most people are, therefore, unable to use touch typing techniques for accessing these characters. When these keys are commonly accessed, such as the xe2x80x9cEnterxe2x80x9d, xe2x80x9cShiftxe2x80x9d, and xe2x80x9cBackspacexe2x80x9d keys, they are typically given a larger surface to make contact more likely and less error prone. Unfortunately, these strategies are not sufficient to enable continuous touch typing for most people working on even the most common tasks.
Third, the fixed position of keyboards inhibits mobility. A keyboard is typically located at a fixed position, such as a desktop or keyboard tray. This requires that the user come to the keyboard and remain there. The user is unable to access a keyboard while engaging in other tasks, such as walking around a warehouse, moving among patient examination rooms, pacing while brainstorming, etc.
Fourth, productivity and ease of use is reduced because a hand must move from the normal keyboard rest position to manipulate the cursor pointing device (typically a mouse, track ball or pointing stick, such as IBM""s TrackPoint(copyright) pointing device). Gross motor movements are almost always required to switch between keyboard input tasks and pointing device tasks. Thus, seamless, quick interaction with the computer is not possible, which reduces productivity and ease of use. While such movements may seem beneficial for relieving muscle strain, this is not the case for the most problematic areas. That is, these movements may relieve muscle stress in the shoulders and back, but they do not reduce problematic wrist and hand strain because pointing devices typically require the same wrist and hand positions as does the keyboard.
Fifth, keyboards and the computers containing them must be sufficiently large for touch typing and ease of use. The size and dexterity of human fingers, combined with the large number of keys on a traditional keyboard, establish a lower limit on the size of keyboards and, hence, the devices that possess them (such as laptop computers). Any technology that enables smaller, easy-to-use devices is highly desirable.
There are three main classes of alternative keyboards that address some, but not all of these problems:
1. Split Keyboards: These keyboards attack the first problem (muscle fatigue and RSI) by dividing the keys into left and right hand segments and reshaping the traditional keyboard to improve hand and arm postures. There are three main flavors of split keyboards:
Fixed-Splitxe2x80x94The keyboard split and shape is fixed. That is, the angle of the keys, their slope, and their tilt is fixed. Examples include the Microsoft Natural Keyboard and the Cirque Wave Keyboard from Cirque Corporation.
Adjustable-Splitxe2x80x94The keyboard split or segmentation is fixed, but certain aspects of the shape, such as the angle, slope, and tilt of each hand""s segment, can be adjusted. Examples include the Comfort Keyboard System from Health Care Keyboard Company, Inc. and the MAXIM Adjustable Ergonomic Keyboard from Kinesis Corporation.
Contouredxe2x80x94These keyboards are not flat; their keys are arranged on curved contours that more closely match the reach and movement of the fingers. Examples include the Kinesis Contoured Ergonomic Keyboard from Kinesis Corporation and the Maltron from PCID Maltron Ltd.
2. Vertical Keyboards: These keyboards are similar to split keyboards, except that each segment of keys is tilted until it is vertical. In this xe2x80x9chandshake positionxe2x80x9d the hands and forearms are considered to be in a neutral position. Examples include the Vertical Split-Keyboard from Ergonomic-Interface Keyboard Systems, Inc. and the ErgoMaster from KMC Concepts, Inc.
3. Chording Keyboards: Chording keyboards partially address most of the problems above. Rather than having a single key per character, as most keyboards do, they require a simultaneous combination of keys to be pressed for each character. The advantage is that fewer keys are required, the device containing the keyboard that can be smaller (e.g., see the DataEgg in-hand computer by E2 Solutions), and in some cases, the keyboard position can be highly adjustable and even mobile. Unfortunately, because they do not use the QWERTY key arrangement, they have a very steep learning curve (15 hours training, 80 hours experience minimum, by one estimate) and they are very slow for typing. Touch typing, in the normal sense of the phrase, is not possible with chording keyboards. Examples include the Twiddler from Handykey Corp. and the AccuKey by AccuCorp, Inc.
Naturally, there are exceptions to these main classes such as the DataHand Professional II from DataHand Systems, Inc. This system has a xe2x80x9cpodxe2x80x9d for each hand. Each pod has a receptacle for each finger that consists of five switches. By moving the fingers against the switches, the functionality of the traditional keyboard is mimicked. As this keyboard has an integrated pointing device, it addresses problems two and four fairly well (new typing skills are required, however). The keyboard is not designed to tilt, so it only partially addresses the first problem and it is not mobile (thus, it does not address the third problem well).
A more complete list of alternative keyboards is provided at http://www.tifaq.org/keyboards.html.
The invention solves the five problems above by offering the following advantages:
1. The ability to use the keyboard in nearly any position or orientation.
2. The ability to change the position or orientation of the keyboard while in use (to reduce fatigue).
3. The ability to exploit the same gestures required for the operation of traditional keyboards, whether QWERTY or DVORAK.
4. The ability to decouple fine and gross motor movements for ease of use and touch typing ability, while maintaining full keyboard expressibility.
5. The ability to operate the keyboard in a physically and electrically disconnected mode (for mobility).
6. The ability to operate the pointer device in any physical position or orientation and without requiring careful repositioning of the hands to resume typing.
7. The ability to provide full-sized keyboard ease of use, while taking up less space when it is not in use.
The invention is a split keyboard that permits unparalleled range of motion while facilitating touch-typing based on the familiar QWERTY, DVORAK or other layouts. It will typically consist of two 17-key xe2x80x9cminixe2x80x9d keyboards, one for each hand. To realize the full expressibility of a 104 key keyboard, the invention senses the wrist position and uses this information to multiply the interpretations of the two sets of 17 keys. As described below, the keyboards may include a pointing device. Furthermore, they may be placed in a static location, such as a desktop, or they may be made free ranging by attaching each to its respective hand using a novel, quick-release mechanism and using an infrared device for communication. Finally, the key arrangement may be contoured or flat and the motion of the key sets may be linear or, more typically, arced.
There are many possible embodiments of the invention, some of which are described below. Each of these embodiments or keyboard solutions is derived in various ways from the following solution elements. Elements one and two are fundamental to all embodiments. Elements three and four are not included in some keyboard embodiments. Each of these elements is believed to be novel for true, non-chording keyboards.
1. Decoupling fine and gross motor movements by: a) restricting the required motions or keystrokes of each finger to a limited number of positions (typically, four or five) that can be reached without moving the hand or employing any other gross motor movement, and b) directly or indirectly sensing the wrist position and multiplying the number of possible interpretations of the keystrokes by the number of discrete wrist angle positions.
2. A means to change the position of the keyboard as the wrist angle is changed such that the keystroke positions are invariant with respect to wrist angle, from the perspective of the fingers.
3. A means to attach the keyboard device to the hand in a manner that does not require grasping and allows easily repeatable keystroke gestures that are invariant with respect to hand or arm position. The primary means described below exploits the observation that the back of each hand, above the middle three metacarpals, moves very little with respect to the fingers. Thus, a very stable brace can be constructed by placing a curved, possibly padded surface across the back of the hand, another surface beneath the palm, a means to create a clamping force between these two surfaces, and providing a way of attaching the keyboard to this brace.
4. A means to access the pointer device and the associated keys (for right and left clicks) without the use of any gross motor movements. Thus, the position of the pointer device will also be invariant with respect to wrist angle.